1. Field of Invention
This invention pertains to a cutting bit for use in mining, construction, and road surface removal. More particularly, this invention relates to a cutting bit including at least one substantially conical or frustoconical carbide or steel pin member for engaging the cutting bit tool holder in order to prevent unwanted rotation of the cutting bit tool with respect to the tool holder.
2. Description of the Related Art
It is well known in the mining, construction/earth moving, and road removal industries to use cutting bits on the perimeter and across the width of a rotary drum, or continuous chain or the like. In this regard, the cutting bits are mounted on bit holders which are in turn mounted on the drum or the chain. These cutting bits are then moved through an orbit and engage the ground, a mine face, or a road surface for the purpose of removing a portion of the surface of these environments. The cutting bits frequently include a tip, or other cutting tool, and a shank. The shank is received in a bit holder; which in turn is mounted on the drum or chain of the cutting or mining machine. It is common in the art for the shank to be rotatably received in the bit holder. However, once it is mounted, in the case of certain configurations of cutting bits, rotation of the cutting bit once secured, and during cutting or mining, is undesired.
Typical of the known art for cutting bits in the mining, construction/earth moving, and road removal industries is U.S. Pat. No. 6,371,567, issued to the Phillip A. Sollami, on Apr. 16, 2002; U.S. Pat. No. 5,374,111, issued to Den Besten et al on Dec. 20, 1994; U.S. Pat. No. 5,833,323 issued to Massa et al on Nov. 10, 1998; and U.S. Pat. No. 7,165,922 issued to Inuzuka on Jan. 23, 2007. Because it is known that debris from the cutting process can foul the junction of the bit holder and bit block making removal of the bit holder from the bit block difficult, much of the known art pertains to providing a means for forcibly removing the bit holder from the bit block. Further, it is known in this and other arts to use keys and associated keyways when it is desirable to limit or prevent rotation of a shank received within a bore or receiver. However, it is also known that breakage of a key or fouling of the keyway makes removal of the tool secured in such manner time consuming and necessitates a repair. What is missing in the art is a dirt and rock cutting tool assembly that includes at least one hardened member for engaging the bit block so as to substantially prevent rotation of a cutting bit secured to the bit block.
Accordingly, it is an object of the present invention to provide an improved dirt and rock cutting bit tool that allows infinite rotational positioning of the cutting bit and that substantially prevents rotation of the cutting bit upon securing the cutting bit holder to the bit block.
Another object of the present invention is to provide a dirt and rock cutting bit tool that utilizes at least one hardened pin member carried by one of the bit holder and bit block in such a manner that the hardened pin bites into the softer metal of the bit block thereby substantially preventing rotation of the bit holder within the bit block upon securement of the bit holder to the bit block.
Yet another object of the present invention is to provide a dirt and rock cutting tool assembly in which the bit holder is secured to the bit block by means of a single bolt thereby making removal of the bit holder from the bit block less difficult.